1. Field
The present disclosure relates generally to a heatsink for a light emitting diode (LED) bulb, and more specifically to a partitioned heatsink for improved cooling of different components of a LED bulb.
2. Description of Related Art
Traditionally, lighting has been generated using fluorescent and incandescent light bulbs. While both types of light bulbs have been reliably used, each suffers from certain drawbacks. For instance, incandescent bulbs tend to be inefficient, using only 2-3% of their power to produce light, while the remaining 97-98% of their power is lost as heat. Fluorescent bulbs, while more efficient than incandescent bulbs, do not produce the same warm light as that generated by incandescent bulbs. Additionally, there are health and environmental concerns regarding the mercury contained in fluorescent bulbs.
Thus, an alternative light source is desired. One such alternative is a bulb utilizing an LED. An LED comprises a semiconductor junction that emits light due to an electrical current flowing through the junction. Compared to a traditional incandescent bulb, an LED bulb is capable of producing more light using the same amount of power. Additionally, the operational life of an LED bulb is orders of magnitude longer than that of an incandescent bulb, for example, 10,000-100,000 hours as opposed to 1,000-2,000 hours.
The lifetime and performance of an LED bulb depends, in part, on its operating temperature. The lifetime of the LED bulb driver circuit may limit the overall lifetime of the LED bulb if the driver circuit operates at high temperature for long periods of time. Similarly, the lifetime of the LEDs that produce the light may be reduced by excessive heat. Additionally, high operating temperatures can reduce the light output of the LEDs.
While both the driver circuit and LEDs are sensitive to high operating temperatures, these components are also responsible for generating heat. LEDs are about 80% efficient, meaning that 20% of power supplied to LEDs is lost as heat. Similarly, the driver circuit that supplies current to the LED is about 90% efficient, meaning that 10% of the power supplied to it is lost as heat.
The operating temperature of a LED bulb depends on many factors. For example, each individual LED produces heat. Therefore, the number and type of LEDs present in the bulb may affect the amount of heat the LED bulb produces. Additionally, driver circuitry may also produce significant amounts of heat.
Other factors may determine the rate at which generated heat is dissipated. For example, the nature of the enclosure into which the LED bulb is installed may dictate the orientation of the LED bulb, the insulating properties surrounding the LED bulb, and the direction of the convective air stream flowing over the LED bulb. Each of these factors may have a dramatic effect on the build up of heat in and around the LED bulb.
Accordingly, LED bulbs may require cooling systems that account for the different sources of heat, the ability of components to withstand elevated temperatures, and the variables associated with the dissipation of heat.